Segnalo un articolo (in inglese) in cui viene spiegato, in modo molto semplice, come implementare il servizio di persistenza su SQL Sevrer di Windows Workflow Foundation.
Persisting Workflows Using WF- Movie Rental Example
Here is an article that shows how to persist running workflows. Persisting long-running workflows is just one of the powerful features of WF, and this article gives a great example. It shows a movie being rented from a store and how the rental metadata is persisted until the movie is due or returned back to the store. The article also shows how to create the Sql data store and how to wire up the core service for handling persistance. Get the solution used for this article here.
Source: Bayer White - .Net Made Easy With WF : Persisting Workflows Using WF- Movie Rental Example
Fonte: http://blogs.msdn.com/pandrew/archive/2007/05/02/wf-persistence-example.aspx